Lacking a relationship to a time base or clock. In asynchronous communications, individual data characters are sent at an arbitrary rate.

The difference between downward and upward (total) radiation; net flux of all radiation.

A rocket designed primarily for routine upper air observations in the lower 250,000 feet of the atmosphere, especially that portion inaccessible to balloons (above 100,000 feet).

An elongated area of relatively low atmospheric pressure. Usually associated with and most clearly identified as an area of maximum cyclonic curvature of the wind flow. The opposite of a ridge.

An instrument used to reveal but not necessarily measure the presence of an electrical quantity. It is used to display the output of a sensing element after suitable amplification and modification. Sometimes called display.

A hygrometer which includes an arrangement for the time recording of atmospheric humidity.

Pertaining to the action or effect of the wind. Derived from the name of the Greek god of the winds, Aeolus.

Any sudden and heavy rain, almost always of the shower type.

In meteorology, an area of low pressure; a low or trough.

A high-altitude sounding system consisting of a small solid- propellant research rocket carried aloft by a large plastic balloon. The rocket is fired near the maximum altitude of the balloon flight.

Physical equipment used in data processing. Compare to firmware, software.

The range of operating conditions of a device within which operating influences are negligible. The range is usually narrow. Reference operating conditions are the conditions under which reference performance is stated and the base from which the values o ...

A measure of the attenuation due to scattering, of light as it traverses a medium containing scattering particles.

An instrument, located at the surface observing station, which is used to record the data presented by a radiosonde aloft.

A hydrostatic principle that pressure supplied to an enclosed fluid is transmitted undiminished to every portion of the fluid and to the walls of the containing vessel.

The amount of moisture which, if available, would be removed from a given land area by evapotranspiration. Expressed in units of water depth.

An instrument which measures the intensity of radiation by determining the amount of chemical change( or fluorescence produced by that radiation.

The line-of-sight distance between two objects.

An instrument developed by K. Angstrom for measuring the effective terrestrial radiation. It consists of four manganin strips, of which two are blackened and two are polished. The blackened strips are allowed to radiate to the atmosphere while the polishe ...

An increase in the central pressure of a pressure system; opposite of a deepening. More commonly applied to a low rather than a high.